We have employed Interferometric Lithography (IL) for sub-wavelength surface texturing
on large area silicon substrates. Low defect density Reactive Ion Etching (RIE) processes have been
developed to transfer the pattern into the silicon using SF
6
plasma. Reflection measurements on the
sub-wavelength textured surface have been carried out and show a substantial reduction from ~30%
to below 4% over the spectrum range from 400nm to 1200nm. IL is a mask-less lithography
technique which is used to define periodic patterns. The theoretical limit of the pitch size of the
structure is half of the wavelength of the light source. Hence, the sub-wavelength patterns can be
achieved easily. Moreover, sub-wavelength texturing requires short RIE processes; most of the
plasma-induced damage on the silicon surface can be avoided.